Exam III: Microbial Metabolism Flashcards
Define “metabolism”
The sum of chemical reactions within a living organism
Metabolism is the chemistry of breaking things down for ____ AND ______ for cellular life
Energy; Building/Making things
Metabolism = ___ + ___
anabolism + catabolism
___ is the synthesis of complex organic molecules from simpler molecules.
Anabolism
___ is the breakdown of complex organic molecules into simper molecules
Catabolism
These kinds of reactions release water…
Dehydration Synthesis
These kinds of reactions use water molecules…
Hydrolytic
Catabolic reactions are generally ___ reactions (water molecules get used).
Hydrolytic
Anabolic reactions are generally ___ reaction (releases water).
Dehydration synthesis
Means “consuming energy”…is related to ____ reactions
Endergonic; Anabolism
Means “produces energy”…is related to ___ reactions.
Exergonic; Catabolism
These are biological catalysts that speed up chemical reactions.
Enzymes
True/False: Enzymes are not consumed in chemical reactions.
True. Enzymes are NOT consumed in the reaction.
Enzymes have a ____ shape to recognize substrates.
Unique
Enzymes are specific for a particular ___ and ___.
Substrate and Reaction
___ is where the enzyme acts on on a particular molecule (protein, RNA, DNA, etc), specifically by attaching to the ___.
Substrate; Active site
True/False: Enzymes participate in chemical reactions, but are not consumed by them.
True. Enzymes are not consumed in chemical reactions. They can function over and over again.
___ (enzyme speed) is the maximum number of substrate molecules an enzyme molecule can convert to product each second.
Turnover number
What is the turnover number for DNA polymerase (DNA synthesis)?
250
What is the turnover number for Catalase (breakdown of H2O2)?
20,000
___ enzymes are made entirely of protein (sequences of ___ that fold up into 3D shape).
Simple; Amino acids
___ enzymes are more complex, and made up of 2 parts.
Conjugated
The protein component of a conjugated enzyme is called the ___.
Apoenzyme
The non-protein component of a conjugated enzyme is called the ___.
Cofactor
An organic molecule that is a cofactor is called a ___.
Coenzyme
Apoenzyme + Cofactor = ___
Holoenzyme
Without a cofactor, apoenzyme is ___.
Not active (Needs a cofactor to work! eg DNA polymerase III)
Enzyme names usually end in -___.
-ase
Elevation above a certain temperature leads to enzyme ___. (What does this mean?)
denaturation (It doesn’t work anymore!)
Most enzymes have a pH ___. Extreme pH can result in enzyme ___.
optimum; devaturation
True/False: Under normal conditions, enzymes are saturated.
False. Under normal conditions, enzymes are NOT saturated.
____ leads to maximal enzyme activity, and the enzyme is said to be ___.
High substrate concentration; Saturated
In a high substrate concentration, the enzyme is doing what?
Going as fast as it possibly can.
Metabolic pathways usually contain many steps, each with an individual ___ at each step. This is known as a _____.
Enzyme; Multienzyme systems
3 different patterns seen in metabolic pathways are:
Linear, Cyclic, Branched
How do you control metabolic pathways, at the level of the enzymes? (2 answers)
Control of enzyme action; Control of synthesis
What are the two types of inhibitors relative to controlling enzyme action in controlling metabolic pathways?
Competitive & Non-competitive
This inhibitor is similar in shape and chemical structure to the substrate
Competitive inhibitor
This inhibitor interacts with a site other then the active site.
Non-competitive inhibitor
This inhibitor may bind reversibly, or irreversibly
Non-competitive inhibitor
This inhibitor fills the active site and blocks the substrate which the enzyme is acting on.
Competitive inhibitor
Inhibition of folic acid synthesis by sulfanilamide, which competes with PAPA for the enzyme’s active site, is an example of what kind of inhibition?
Competitive inhibition
This inhibitor binds somewhere else, or changes shape
Non-competitive inhibitor
When the end product of a metabolic pathway is often a non-competitive inhibitor of that pathway, this is known as ___.
Feedback inhibition
What is the purpose of feedback inhibition?
It prevents the cell from wasted energy.
This is when cells use electrons in a “hot potato” way to generate ATP
Redox Reaction
Oxidation is …
Oxidation is the removal of electrons from a molecule.
Reduction is …
Reduction is the gaining of electrons by a molecule
True/False: Oxidation and reduction reactions may be coupled together, or occur on their own individually.
False. Oxidation and reduction reactions are ALWAYS coupled (redox reactions).
ATP has “high energy” (or ____), which allow the energy to __________.
Unstable bonds; Allows the energy to be released quickly and easily.
Glycolysis is an example of what method of ATP generation?
Substrate level phosphorylation
Electron transport chain is an example of what method of ATP generation?
Oxidative phosphorylation
In substrate level phosphorylation, ATP is generated when a ___ ___ phosphate is transferred directly to ___ from a phosphorylated substrate
High energy; ADP
ATP is made from ___
ADP
In oxidative phosphorylation, electrons are transferred from ___ ___ through a series of electron ___ to O2 or other oxidized inorganic or organic molecules.
organic compounds; carriers
When electrons are transferred from organic compounds through a series of electron carriers to O2 or other oxidized inorganic or organic molecules, this sequence is known as ____.
Electron transport chain
In the electron transport chain, energy is released during the transfer of electrons from one carrier and is used to make ___ from ___.
ATP from ADP.
The third mechanism of ATP generation (which isn’t dealt with in detail in this class) is called ___.
Photophosphorylation
In carbohydrate catabolism, microbes use two general processes to generate energy from carbohydrates. They are ___ and ___.
Cellular respiration and Fermentation
Both methods of carbohydrate metabolism in microbes start with what process?
Glycolysis
The first step in cellular respiration is ___.
Glycolysis
The second step in cellular respiration is ___.
Intermediate step
The third step in cellular respiration is ___.
Kreb’s Cycle (aka TCA Cycle)
The fourth step in cellular respiration is ___.
Electron transport chain
Glycolysis is when ___ is oxidized to ___ with ___ and ___ produced
Glucose; Pyruvic Acid; ATP; NADH
NADH and FADH2 are both _____.
Energy-containing
In the intermediate step of cellular respiration, ___ is converted to ___ with ___ produced.
Pyruvic Acid; Acetyl CoA; NADH
In the Kreb’s Cycle step of cellular respiration, ___ is oxidized to ___ with ___, ___, and ___ produced.
Acetyl CoA; CO2; ATP; NADH; FADH2
In the electron transport chain step of cellular respiration, ___ and ___ are oxidized through a series of ___ reactions, and a considerable amount of ___ is produced.
NADH; FADH2; redox; ATP
Steps 1-5 of glycolysis is called the ____ stage.
Preparatory
Steps 6-10 of glycolysis is called the ___ stage.
Energy
Glycolysis starts out with a ___-carbon ___ molecule.
6-carbon; Glucose
The preparatory stage of glycolysis nets __(#) ATP molecules.
-2 (uses 2 ATP molecules to “prime the pump”)
The preparatory stage of glycolysis results in __(#) molecules of ___-carbon molecules of ________.
2; 3-carbon; Glyceraldehyde-3-phosphate
The energy phase of glycolysis starts out with __(#) molecules of ______.
2; Glyceraldehyde-3-phosphate
In glycolysis, for every glucose molecule, will result in __(#) _________ oxidized to __(#) _____.
2 Glyceraldehyde-3-phosphates;
In glycolysis, for each one glucose molecule, there will be a net gain of __(#) ATP produced, and __(#) NADH produced.
4 ATP; 2 NADH
The gain of ATP energy molecules occurs in glycolysis due to the process of _______.
Substrate level phosphorylation
The final outcome of glycolysis is the production of __(#) molecules of ___, which are __-carbon molecule.
2; Pyruvic acid; 3-carbon
What will the NADH molecules that are produced be used for?
To make more ATP
After glycolysis, pyruvic acid can now undergo either ___ or ___.
fermentation or respiration
The two types of cellular respiration are ___ and ___.
Aerobic respiration; Anaerobic respiration
In aerobic respiration, oxygen is/is not required, and the final electron acceptor is ___.
oxygen IS required; O2
In anaerobic respiration, oxygen is/is not required, and the final electron acceptor is ___.
oxygen is NOT required; an inorganic molecule other than O2.
This is an alternative to glycolysis that involves the breakdown of 5 carbon sugars, and makes important intermediates (nucleic acids).
Phosphogluconate pathway
This is an alternative to glycolysis that involves the glucose breakdown for organisms that don’t have all the necessary enzymes for glycolysis (for example, organisms in the ___ spp family).
Entner-Doudoroff reaction; Pseudomonas
True/False: The alternatives to glycolysis are more efficient than glycolysis.
FALSE. The alternatives (phoshogluconate pathway and Entner-Doudoroff reaction) are NOT as efficient as glycolysis.
True/False: In the intermediate step of cellular respiration, pyruvic acid is converted to acetyle CoA with NADH produced.
True
The Kreb’s cycle is the __(#) step in cellular respiration, and is also known as ___.
3rd; TCA (Tricarboxylic acid) Cycle or citric acid cycle
In the Kreb’s cycle, a large amount of potential energy stored in ___ is released by a series of ___ reactions that transfer ___ to the electron carrier coenzymes (NAD+ and FAD).
Acetyl CoA; Redox; electrons
In regards to the Kreb’s cycle, NAD+ and FAD are ___.
Electron carrier coenzymes
True/False: The intermediate step of cellular respiration is an energy generating step.
True
In the intermediate step of cellular respiration, ___ is converted to a __-carbon compound (known as ___).
pyruvic acid; 2 carbon; decarboxylation
In the intermediate step of cellular respiration, the 2-carbon acetyl group combines with ___ through a high energy bond. ___ is reduced to ___, which produces energy.
Coenzyme A; NAD+; NADH
In the Kreb’s Cycle, for every molecule of glucose, there are __(#) acetyl-CoA molcules which will generate: __(#) CO2, __(#) NADH, __(#) FADH2, __(#) ATP.
2 acetyl CoA; 4 CO2; 6 NADH; 2 FADH2; 2 ATP
The Krebs Cycle begins and ends with ___
Oxaloacetate and acetyl CoA
Glycolysis has __ steps, uses __ ___ molecules for energy, and generates the following energy:
Glycolysis:
10 steps, 2 ATP used, Generates 4 ATP (Net 2 ATP), 2 NADH
If you can interfere with ___ ___ in glycolysis pathway, you can ___ ___ the ability for that organism to generate ___.
Enzyme function; Take away; ATP
Intermediate step has __ steps, uses ___ molecules for energy, and generates the following energy:
Intermediate Step:
1 step; Uses no energy; Generates 2 NADH
Kreb’s Cycle/TCA step has __ steps, uses ___ molecules for energy, and generates the following energy:
Kreb’s Cycle:
9 steps; Uses no energy; Generates 2 ATP, 6 NADH, 2 FADH2
All the reduced ___ ___ ___ (2 NADH from glycolysis, 2 NADH from pyruvic acid to acetyle CoA conversation, and 6 NADH and 2 FADH2 from the Kreb’s Cycle) make their way to the electron transport chain
Coenzyme Electron Carriers
The electron transport chain indirectly transfers the energy from the ___ to ___.
Coenzymes; ATP
The sequence of carrier molecules capable of oxidation and reduction.
Electron transport chain (ETC)
The release of energy in the electron transport chain is coupled to the generation of ATP by _____.
Oxidative phosphorylation
The 3 classes of ETC (electron transport chain) molecules are:
Flavoproteins; Coenzyme Q (Ubiquinone); Cytochromes
These ETC carrier molecules have an iron-containing group (heme) which can exist in alternating reduced (Fe2+) and oxidized (Fe3+) forms.
Cytochromes
These ETC carrier molecules are a small non-protein carrier molecule, and are found ___.
Coenzyme Q (Ubiquinone); found all over.
These ETC carrier molecules contain a coenzyme called flavin mononucleotide (FMN) that is derived from riboflavin. These molecules are also capable of ___ oxidations/reductions.
Flavoproteins; alternating oxidations/reductions
ETC is located in the ____ of the ___ in eukaryotes
inner membrane; mitochondria
ETC is located in the ___ of prokaryotes
plasma membrane
ETCs are the same in what way?
They all share the same goal, which is to capture energy into ATP
How are bacterial ETCs unique?
They are diverse (particular carriers and their order); Some bacteria have several types of ETCs
How are eukaryotic ETCs unique?
They are more unified and better described (better studied)
In a mitochondrial ETC, the process starts with what enzyme, acting on what molecules?
NADH dehydrogenase; NADH
The final step of mitochondrial ETC involved what?
Pumping of H+ ions into the intermembrane space
The electrons pumped into the intermembrane are picked up by a final acceptor? What is it, and what does it create?
O2, creates water (H20)
What is created when there is an excess of protons pumped to one side of the membrane?
Proton gradient; Proton motive force
What happens to the protons in the intermembrane space: What causes them to diffuse back across the membrane into the cell?
Chemiosmosis
What enzyme uses the energy released by the diffusion of H+ across the membrane? It synthesizes ___ from ___.
ATP synthase. It synthesizes ATP from ADP.
